We have a Lumina LSC400 controller setup to use E-Prime with Siemens 3T MRI scanner. However, one of the response pad button (yellow) does not register a key press and on the controller yellow LED stays ON continuously.
Other buttons (blue, green and red) all work fine and register correctly on the controller to each key press.

Do you have any suggestions/solutions on how to clear/reset yellow LED light from the controller and to make button 2 (yellow) register a response to a key press?